<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let xhr=new XMLHttpRequest()
        xhr.open('post','http://localhost:8888/test/fourth')
        xhr.setRequestHeader('content-type','application/x-www-form-urlencoded')
        xhr.onreadystatechange=()=>{
            if(xhr.readyState===4){
                if(xhr.status===200){
                    console.log(JSON.parse(xhr.responseText));
                }
            }
        }
        xhr.send('name=gaowei&age=18')
    </script>
</body>
</html>